Why do first-born children live together with parents?

In this paper, we analyze the strategic residential location choices of multiple siblings who receive childcare assistance from their parents. Our three stage game yields a theoretical result that first-born children are more likely to live together with or close to their parents than second-born children, which is supported by our estimation results using Japanese micro-data. We also empirically show that the childcare assistance from parents is one of the determinants of the residential location choice of siblings. This paper is the first to succeed in explaining the residential location choice of siblings in Japan using economic incentives.